An electronic device for cellular communications may support wireless communications on plural radio frequency bands (also referred to as channels) for a radio access technology. The electronic device may also support multiple radio access technologies, in which case the electronic device may support one or more frequency bands for each of the supported radio access technologies. Typically, not all supported bands are used simultaneously. Rather, the electronic device is configured to switch to a desired frequency band and/or radio access technology using one or both of software or hardware tuning technologies. The total number of bands supported in current electronic devices varies depending on the specific electronic device, the manufacturer, the supported radio access technologies, etc. Exemplary cellular radio access technologies may operate in both the licensed and unlicensed frequency spectra and include, but are not limited to, GSM, GPRS, UMTS and LTE, and sub-categories thereof.
Typically, the electronic device has stored data regarding a default network (also referred to as a home network) to which it connects. However, there are situations in which the electronic device cannot find the default network. In this event, the electronic device starts a scan procedure in which each supported channel of each supported radio access technology is scanned to identify a network with which to communicate. This is often referred to as a “full band scan”. Full band scanning can take up to several minutes to complete scanning of each supported channel, although the scanning may be interrupted if a certain condition occurs such as identifying a preferred network or finding another suitable radio access network. Typically, the scan involves scanning each supported channel in a serial manner (one after another) and in a default order.
Different techniques are known in the art to adapt the scanning order of the full band scan, to shorten the time required to establish a network connection. For example, US2016/026988 proposes to analyze subscription information available on the SIM card in the electronic device to identify a country or region of the world in which the electronic device is most likely being used. From the identified country or region, the electronic device configures a prioritized band scan order that starts with the most likely frequencies and radio access technologies. WO2017/153286 proposes to similarly prioritize the band scan order based on the probable location of the electronic device derived from application software on the electronic device, such as an appointment book, email, text messaging, social networking, etc. US2016/0157168 proposes to similarly prioritize the band scan order based on a current location determined by short-range wireless communication, e.g. based on a MAC address obtained from an incoming WiFi-signal.
Even if the full band scan is prioritized in accordance with the foregoing, a battery-powered electronic device that is frequently moved near or across borders of countries or regions that apply different radio access technologies and/or radio frequency bands may be rapidly drained of battery power.